Self-Renewing Presomitic Mesoderm Progenitor Lines Reprogrammed from human urine cells [Reprogramming ATAC-seq]

Vertebrae formation is the defining feature of all vertebrates1,2. Yet, each vertebrate species appears to have a unique timing mechanism for forming somites along the vertebral column3-5. Human vertebrate formation remains poorly studied due to technical and ethical limitations. Here we report the generation of self-renewing stem cells with characteristic presomitic mesoderm (PSM) features by reprogramming epithelial cells isolated from human urine. These induced expandable presomitic mesoderm progenitor cells (UiPSM) proliferated extensively for more than 30 passages in chemically defined conditions, robustly producing 1040 UiPSM cells. UiPSM established presomitic mesodermal transcription profile, not detected pluripotency, ectoderm and endoderm related genes. UiPSM developed into presomitic mesodermal lineage cells, such as skeletal muscle cells(skm), osteoblast and chrondroblast cells in vivo and vitro, when transplanted UiPSM derived human skm cells in muscle injury model, the skm cells can survive in vivo and contribute to muscle regeneration up to one month. Thus, UiPSM is a powerful system to study human somite development and provide strategies for regenerative medicine in musculoskeletal system